No. 16 Article 3/July 10, 2009

Western Corn Rootworm Emergence Has Begun

On June 29, I received a first report of a western corn rootworm adult sighting near Carlinville. The corn was just beginning to tassel. Joe Spencer, an entomologist with the Illinois Natural History Survey, indicated on July 2 that his research team found corn rootworm larvae and pupae in their plots located near Champaign. I believe that by late this week, western corn rootworm adults will begin to emerge across central Illinois. The emergence is somewhat later this year, though not by much. We will begin our annual root injury evaluations about a week later this season (July 20) than in previous years.

Producers are encouraged to look for signs of excessive root injury, such as lodged corn plants, in their fields and evaluate the level of control afforded by their transgenic corn or soil insecticide. I look forward to your observations. As adults become more numerous, don't forget to monitor plants for silk clipping to protect the pollination process. Consider a treatment if there are more than 5 beetles per plant and pollination is not complete.--Mike Gray

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